Systems and methods for remotely viewing page layouts

ABSTRACT

A system and methods for remotely viewing a dynamically generated page layout is described. The page layout can represent a reader ordering of pages defined as part of a print production job. Alternatively, the page layout can represent an arrangement of pages based on information defined as part of a print production job.

REFERENCE TO RELATED APPLICATION

This application is a Divisional of prior U.S. patent application Ser.No. 11/210,203, filed Aug. 23, 2005, which claims priority from U.S.Patent Application No. 60/603,550, filed Aug. 24, 2004, each of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

This invention pertains to producing printed matter. More specificallythe invention relates to remote, computerized access to informationabout producing printed matter.

BACKGROUND

Historically, facsimiles (or proofs) of final printed matter have beengenerated to enable the printer and print buyer to increase confidencein the final printed matter before the resources required to producethem have been committed.

Production of printed proofs, using less expensive resources (e.g.inkjet printer), was one method of proofing the content and printingprocesses. A proof could comprise a single page from a multiple pageprint job. Alternatively a proof could comprise a layout of anarrangement of pages from one or more print jobs. The layout couldinclude selected pages that have specific proofing requirements (e.g.verifying content or verifying color). The layout could also includepages arranged as they would finally be printed to verify registration,layout or other aspects of the content or printing process. Productionof printed proofs still included the cost of ink and paper consumablesand presented logistical challenges for approval by reviewers located inone or more remote locations.

Soft proofing addressed some of the limitations of printed proofs byeliminating consumable costs and enabling remote and collaborativereview of electronic proofs of the printed matter. The prior art teachescreation of electronic data (soft proof) representing a single page orimposed page layout. Independent remote viewing of the soft proof wasenabled by delivering the soft proof to each reviewer. Delivering thesoft proof to each location at one or more resolutions required foreffective reviewing was problematic because of the computing andcommunication resources consumed and the latency in delivering theproof. Collaborative viewing was problematic with this method.

The prior art also teaches collaborative viewing of single pages where aserver delivers a soft proof to multiple reviewers. The server renderedthe same view of the page for each reviewer. By delivering only a partof the rendered page at the desired resolution the resource consumptionand latency was reduced.

Remote and collaborative viewing of page layouts that is efficient andconvenient remain as limitations in the prior art.

SUMMARY OF INVENTION

This invention provides systems and methods for remotely viewing adynamically generated page layout on a computer system display. Viewingpages arranged in ways that depend on the user's intent providesconvenience and efficiency to the user. Information about print jobs canbe used to generate a layout and display it remotely. Alternatively,user input can be used to generate a layout and display it remotely.Preferred embodiments are based on client/server software architecturewith components communicating using a network. Preferred clientembodiments operate in a web-browser environment. A system according toone embodiment of the invention includes:

-   -   1. At least one print production software module, located at        least one server location. A print production software module        provides the function of printing jobs, comprising multiple        pages, while maintaining information about the jobs in a jobs        database.    -   2. At least one jobs database module, located at least one        server location, for storing information about jobs.    -   3. At least one job information software module, located at        least one server location. A job information software module        provides the functions of:        -   communicating information about jobs from a jobs database to            client software modules;        -   receiving page layout view requests from a client software            module, a request containing information sufficient to            generate a page layout and identify the part of the layout            of interest;        -   generating a partial page layout image corresponding to a            request; and        -   communicating the partial page layout image to the client            software module.    -   4. At least one client software module, located at least one        client location. A client software module communicates with a        job information software module to provide the functions of:        -   obtaining information about jobs;        -   requesting a page layout view based on information about            jobs;        -   obtaining a partial layout image corresponding to the            requested page layout view; and        -   displaying the partial layout image.    -   5. At least one network to facilitate communication between        modules operating on separate computer systems.

BRIEF DESCRIPTION OF DRAWINGS

In the drawings which illustrate non-limiting embodiments of theinvention:

FIG. 1 is a block diagram illustrating the functional components of oneembodiment of the invention.

FIG. 2 is a diagram illustrating a sequence of interactions betweenfunctional components according to one embodiment of the invention.

FIG. 3 is a diagram illustrating a reader-spread page layout.

FIG. 3A is an expanded view of the left side page shown in FIG. 3.

FIG. 4 is a diagram illustrating the structure of a jobs databaseaccording to one embodiment of the invention.

FIG. 5 is a diagram illustrating the relationships between aspects of anexemplary job's information.

DETAILED DESCRIPTION

Throughout the following description, specific details are set forth inorder to provide a more thorough understanding of the invention.However, the invention can be practiced without these particulars. Inother instances, well known elements have not been shown or described indetail to avoid unnecessarily obscuring the invention. Accordingly, thespecification and drawings are to be regarded in an illustrative, ratherthan restrictive sense.

FIG. 1 is a block diagram illustrating the components of one embodimentof the invention. This diagram depicts multiple client software 110located at multiple client locations 101A-B. Client software 110A-C canbe used by an employee, agent, or customer of a printing company thatoperates a print production software system. As an example, clientsoftware 110 enables a customer to upload files to be printed, toobserve the status of a print job and to provide feedback on theprocessing of a print job. Remotely proofreading a page layout that isgenerated on demand is one novel aspect of the invention.

At a client location 101, client software 110 can be executed on acomputer system. In a preferred embodiment, client software 110 executeswithin a web browser environment. Other environments, including nativeoperating system application program environments, are possible. Clientsoftware 110 is capable of communicating with at least one jobinformation software 120 located at a server location 102A-C. In someembodiments, client location 101 and server location 102 are the same.

Job information software 120A-C provides client software 110 withinformation about print jobs. Job information software 120 can beconfigured to communicate with multiple jobs databases 130A-B. Jobinformation comprises at least information about pages to be printed aspart of a print job, including at least the page description (e.g. PDFlanguage) for each page in the job. Throughout the description, the termpage is used to represent a unit of artistic content. It is understoodthat other formats of artistic content are within the scope of theinvention.

Print production software 140A-C is responsible for printing jobs andmaintains a jobs database 130A-B corresponding to jobs that have or areto be printed under its control. The nature and extent of jobinformation stored in jobs database 130 depends on the embodiment ofprint production software 140. Job information may include informationdescribing how to process the job, information about processing stepsthat have occurred, job security information, and other information. Insome embodiments, job information software 120 communicates with printproduction software 140 to request or receive updates to jobinformation.

A server location 102 can comprise one or more computer systems withsoftware and database modules allocated amongst the computer systems.For example, a single computer system can host all three modules.Alternatively, each can be distributed amongst more than one computersystem to balance the processing load. When modules are distributedamongst computer systems, networks 150A-D facilitate communicationbetween the modules. Distribution amongst multiple server locations 102is also possible. As an example, job information software 120B residesat location 102B and is in communication with jobs databases 130A-B vianetworks 150A-B. Similarly, print production software 140B and 140C arepart of the same print production system and store job information atjobs database 130B via networks 150B-C. Similarly, client software 110can also be hosted by a computer system at server location 102.

Network 150A-D can comprise equipment and communication links of avariety of types. Examples include wired or wireless types; andpersonal, local area or wide area types. A variety of communicationprotocols can also be utilized.

In one preferred embodiment of the invention, Creo's Prinergy® workflowsoftware comprises print production software 140 and jobs database 130module. In the same embodiment, Creo's Synapse Insite software comprisesclient software 110 and job information software 120 operating asinternet-based client and server applications respectively.

FIG. 2 is a diagram illustrating an exemplary sequence of interactionsbetween functional components according to one embodiment of theinvention. User 201 operates the computer system that runs clientsoftware 110. User 201 interacts with the computer system through inputand output devices. Exemplary input devices include a keyboard, mouseand microphone. Exemplary output devices include a display monitor andaudio speakers. For example, user 201 provides input to computer systemto start 210 client software 110. Start 210 input can include displaypreferences and the identity of job information software 120.

In response to start 210 input, the client software 110 presents aninitial display on the monitor and sends a request job information 211message to job information software 120. Information about user 201 canbe supplied in the message (or later in response to a query by jobinformation software 120) to determine how job information software 120will respond to this and other messages. Access to features or jobs canbe restricted. Other aspects of the interaction can also be determinedbased on a user 201 profile maintained by job information software 120or print production software 140.

In response to request job information 211 message, job informationsoftware 120 obtains available job information 212, corresponding tomultiple jobs, from one or more job databases 130. Job information 213message, comprising some part of available job information 212, is sentto client software 110 in reply. Job information 213 includes, for eachjob, at least a job identifier and information about pages associatedwith the job.

Upon receipt of job information 213 message, client software 110presents job display 214. The information available to display may becomplex and thus can be presented and navigated in various ways. Onepresentation embodiment provides a summary of all jobs included in jobinformation 213. User 201 can provide select job 215 input to requestmore information about a job. In response, client software 110 presentsjob detail display 216.

An exemplary job detail display 216 may include a summary of each pagecurrently associated with the job. The page summary may include athumbnail preview of the page, page description file information, pageapproval status, requested user activities, annotations supplied byother users, and print production processing information. A job detaildisplay 216 may include other information about the job as be describedbelow.

Assume one requested user activity includes a request to approveselected pages. Pages may be viewed individually as is taught by theprior art. Alternatively, and exemplary of the current invention, alayout of pages may be advantageously viewed where the layout isgenerated based on input from user 201. Examples of generated layoutsinclude:

-   -   a reader-spread layout where two pages are arranged adjacently        with a left-page side and a right-page side;    -   an arrangement of pages where two or more pages are arranged to        fit a specified area; and    -   a precise arrangement of two or more pages.

A reader-spread layout may be advantageous for viewing the pages similarto how the consumer will read the printed job. An arrangement of pagesmay be advantageous for viewing pages that will be printed on a singleprinted medium. A precise arrangement of pages may be advantageous forinspecting the geometrical relationship of pages and process controlinformation that will be printed on a single printed medium. User 201provides select page layout view 220A input to the client software 110indicating the type of layout desired. For illustrative purposes, assumea reader-spread layout is selected.

In response, client software 110 performs calculate view information221A activity corresponding to the initial view. View informationdetermines what part of the page layout is to be displayed. It alsodetermines the resolution of the partial page layout image. First,client software 110 determines the available display area and the numberof display pixels. Next, client software 110 determines the full size ofthe layout based on job information 213. In a reader-spread example, thepage layout dimensions are determined from the maximum height of thepages and by adding the width of each page. If two pages have differentdimensions, rules can be established to determine their relativevertical positioning (e.g. aligned bottoms, aligned tops, or centered).Next, client software 110 obtains the user 201 supplied zoom factor anddisplay area position, relative to the complete page layout, todetermine the dimension of the partial page layout that will bepresented in the display. According to one embodiment of the invention,the initial display shows the complete page layout to simplify theactivity. Finally, client software 110 calculates the requiredresolution of the partial page layout image based on the number ofdisplay pixels and the dimensions of the partial page layout.

Once view information is calculated, client software 110 sends the viewinformation along with page identities as part of request layout image222A message to job information software 120. In response, jobinformation software 120 obtains page layout information 223A from jobsdatabase 130, including at least information about the requested pages.Job information software 120 then performs generate page layout 224Aactivity. At least two alternative embodiments exist for the exampleactivity. The two embodiments are described below. The activitycompletes with job information software sending partial page layoutimage 225A message to client software 110 in reply. The image may beoptionally compressed before sending.

In response, client software 110 presents the image to the user as onepart of layout view 226A. Upon examining layout view 226A, user 201 maychoose an action associated with one or more pages. As an example, apage whose status is unapproved can be approved by providing page action230 input. Client software 110 responds by sending page request 231message, including the approval action and the page identity, to jobinformation software 120 which in turn submits a job update request 232message to print production software 140 on behalf of user 201. If theupdate to the job is allowed, job update 207B is recorded in jobsdatabase 130.

Independent of job information software 120 activities, print productionsoftware 140 can update jobs database 130. As an example, printproduction action 206, representing creation of a new job, adding a newjob file or completion of a processing step can occur at any time. Itresults in job update 207A being recorded in jobs database 130.According to one embodiment, the information in job update 207 is notutilized by job information software 120 until client software 110 sendsrequest job information 211 message, which may be periodically or afterspecific client software 110 events. Other schemes, that provide atimelier update of job information to client software 110, are possible.

While examining layout view 226B, user 201 may determine that adifferent view of the page layout is required. For example, user 201 canzoom into a specific region of the current view, zoom out so that aspecific area of the complete page layout occupies the display area ormove the display area over the page layout while maintaining the currentresolution. As an example, user 201 provides select page layout view220B input to client software module 110 indicating a modifiedpositioning of the display area over the page layout and a modified zoomfactor. Client software 110 and job information software 120 respond asdescribed above. Specifically, user 201 provides select page layout view220B input to the client software 110 indicating the type of layoutdesired. In response, client software 110 performs calculate viewinformation 221B activity corresponding to the initial view. Once viewinformation is calculated, client software 110 sends the viewinformation along with page identities as part of request layout image222B message to job information software 120. In response, jobinformation software 120 obtains page layout information 223B from jobsdatabase 130, including at least information about the requested pages.Job information software 120 then performs generate page layout 224Bactivity. The activity completes with job information software sendingpartial page layout image 225B message to client software 110 in reply.In response, client software 110 presents the image to the user as onepart of layout view 226B. Upon examining layout view 226B, user 201 maychoose an action associated with one or more pages.

In addition to navigating a page layout, user 201 can also filter whichcolor channels to present in the display by providing filter criteria aspart of select page layout view 220 input. Information about colorchannels can be determined from information about pages obtainedpreviously. According to one embodiment, pages initially processed byprint production software are defined with a consistent color space. Thecolor space may correspond to the color space of the device that willproduce the final printed result. As an example, a printing press withCMYK process inks and selected spot inks may have a corresponding colorspace definition that includes those colorants.

According to one embodiment, job information software 120 supportscolor-filtered viewing by processing each page description into separatepage description files, each corresponding to a single color channeldefined by a color space. The color-separated page descriptions can becached to improve subsequent page layout image rendering performance.When a page layout image is generated, page content corresponding toeach view-enabled colorant is rendered to the color space of the displaydevice (e.g. RGB). The resulting rasters are composited to form a singleraster.

For example, assume a complete page layout view where each pagedescription in the layout defines content with CMYK colorants, but onlythe cyan and magenta colorants are enabled in select page layout view220. Four color separated page description are generated for each page.The resulting cyan and magenta page descriptions are rendered andcoincident RGB pixel values (corresponding to the cyan and magenta colorseparations for a page) are combined to form the layout image.

Prior to the step of color separating the page descriptions, jobinformation software 120 can match the colors in the page descriptionsto a specific printing profile (e.g. corresponding to the final printingprocess). This can involve adjusting colorant values and/or substitutingselected spot colorants with process colorant recipes. Color-matchingprofiles and recipes can be part of job information 213.

Reader-Spread Layout

FIG. 3 is a diagram illustrating a reader-spread page layout.Reader-spread page layout 301 comprises a left-side page 310 and aright-side page 320. An exemplary left-side page 310 is also illustratedin an expanded view in FIG. 3A. The page description for left-side page310 is illustrated including a trim-box 314, which defines the geometryused to trim the printed result. The area between trim-box 314 and theboundary of page 310 is known as bleed. Page description content may bedefined to display in the bleed. For example, page content 311 does notdisplay in the bleed, page content 312 displays only in the bleed andpart of page content 313 displays in the bleed. User 201 can requestthat layout view 226A or B include or exclude the bleed. Softwaremodules consider this when calculating page layout dimensions anddisplay positioning.

A reader-spread layout of pages can be based on an arbitrary pair ofpages or on an ordering of pages. FIGS. 4 and 5 illustrate aspects ofthe invention for page layouts based on an ordering of pages. FIG. 4illustrates the structure of data corresponding to jobs database 130.FIG. 5 illustrates a portion of job information 213 corresponding to anexemplary job 402. Four page descriptions 452A-D are illustrated in FIG.5. No ordering of these pages is implied. In fact, it may not bepossible to determine a meaningful ordering from the page descriptionsthemselves. Pages may originate from separate files produced atdifferent times or there may be duplicates of pages representing contentthat varies based on regions where the job is printed.

Page set 441B illustrates a page ordering data structure defined by job402. It comprises an ordered set of page positions 443I-M. The orderingcan imply a reader ordering or some other ordering. Each page position443 can be associated with a page description 452. Alternatively, as inthe case of page position 4431, no association exists. This may occurbecause the corresponding page description has not yet been submitted toor processed by print production software 140. Reader-spread position510 is data, whose value is determined by user 201 input, indicating theposition in page set 441 corresponding to a reader-spread view.Reader-spread position 510 identifies both a left-side and right-sidepage position. In the example of FIG. 5, the left-side page correspondsto page description 452B and the right-side page corresponds to pagedescription 452A. Read-spread position 510 can be positioned at the endsof page set 441 so that only a left-side page or right-side page isincluded in the page layout.

Request layout view 222A-B can include reader-spread position 510 andthe identity of page set 441. Alternatively, request layout view 222A-Bcan provide a client-generated page set and corresponding reader-spreadposition 510. User 201 can easily navigate a page set by providing nextand previous inputs to client software 110.

As indicated above, at least two generate page layout 224 activityembodiments exist for generating a reader-spread page layout. The firstembodiment comprises rendering a part of each page description andassembling the two partial images. The second method comprisesassembling page descriptions into a reader-spread layout description andrendering part of the layout description. In a preferred embodiment, thefirst method is utilized.

The method of the preferred embodiment begins by job informationsoftware 120 rendering the page descriptions for each page. Only theparts of each page that correspond to the part of the layout that isvisible in the display are rendered. This reduces latency and minimizesresource utilization. Client software 110 provides the coordinates ofthe region of each page to be rendered (in the page coordinate system)based on information about the pages and user 201 input. Twocolor-composited rasters corresponding to the visible parts of each pageare then assembled by job information software into a reader spread toform one image. If the display is positioned over only one page thenonly one set of page descriptions is rendered.

The method of the alternate embodiment begins by job informationsoftware 120 assembling the page descriptions. Assembly must take intoaccount user input, such as preference for viewing bleed. For example,client software 110 provides the bleed viewing preference andcoordinates of the visible region of the page layout (in the layoutcoordinate system) based on information about pages and user 201 input.Job information software 120 renders part of each color-separated pagelayout description and composites the rasters to form one image.

Arrangement Layout

In one embodiment of the invention, the reader spread method is extendedto create a different arrangement of two or more pages. As an example,jobs database 130 can contain information describing rules fordynamically generating a layout of an arbitrary collection of pages tofit a medium of some size. Exemplary rules can determine whether torotate pages, determine spacing between pages, and determine spacingbetween the edges of a page and the medium. Any number of rules can bedefined that guide software modules to determine the geometry of thepage arrangement. Alternatively, software modules can share a functionthat is used to determine dynamic layouts. User 201 can influence theapplication of rules by providing input to client software 110. Forexample, rules can be organized into schemes (e.g. best fit, head tohead) that produce different results with user 201 selecting theappropriate scheme.

As another example, the job can contain a pre-defined layout thatspecifies the precise position of pages in a page layout. An arrangementof pages that respects the relative positioning, but without respectingprecise geometric transformations, can be derived by the softwaremodules. This may be advantageous for conveniently viewing the pagesthat will ultimately be printed on a surface of a specific mediumwithout wasting display real estate. In this embodiment, client software110 provides the identity of a pre-defined page layout (see pre-definedarrangement layout below) to job information software 120, which in turndetermines the associated pages and derives the page layout based on jobinformation 213.

Precise Arrangement Layout

In one embodiment of the invention, the reader spread method is extendedto create a precise arrangement of pages and optionally other content.Referring to FIG. 4, jobs database 130 comprises multiple jobs 401. Eachjob 402 (of multiple jobs 401) comprises a job identifier 410, multipleimpositions 420, multiple page sets 440 and multiple pages 450. Eachimposition 421 (of multiple impositions 420) may comprise multiplesignatures 422 and comprises at least one signature 423 of multiplesignatures 422. Each signature 423 comprises at least one sheet 427 (ofa plurality of sheets 426). Each sheet 427 of plurality of sheets 426includes at least one surface 429 of surfaces 428. A surface defines atleast one geometry 431 of a plurality of geometries 430 for contentdefined elsewhere. Geometry 431 precisely defines the positioning of theassociated content on the surface 429 (multiple surfaces 429A-G depictedin FIG. 5). It can also provide information enabling transformation ofcontent to align with geometry 431.

Imposition 421 is associated with a page set 441 to define a pageordering for the imposition. Signature 423 can comprise marks 424 thatappear on the printed material. Examples of a mark 425, used to controlproduction processes, include information derived from the job (e.g. jobname, date, and customer name), color calibration information andfinishing information. Each geometry 431 is associated with a pageposition 443 selected from page positions 442 (which in turn isassociated with a page description 452 of a page 451) or a mark 425.During print production, the position represented by geometry 431 issubstituted with the associated content to produce an imposed layout forsurface 429 that can be rendered.

FIG. 5 illustrates an exemplary job 402. One sheet 427 (not shown) isdepicted as front surface 429A and back surface 429B. Surfaces 429A-Bare positioned on opposite sides of sheet 427 so that their edgesadjacent to line 501 align. Geometries 431A-L are illustrated to showcontent positioning. Geometry 431A is associated with page position 443Ain page set 441A as indicated by a dashed arrow. Geometry 431Arepresents content positioned with no rotation on the lower rightportion of surface 429A. Geometries 431A-L are based on the intendedfolding, cutting and binding of sheet 427 that will occur afterprinting. In this example, sheet 427 is folded first along line 502 sothat front surface 429A is visible. Next, it is folded along line 503 sothat geometry 431A is in front. When cut and bound, the pages will readin reader-order defined by page set 441A.

As with the other embodiments, color correction, color filtering andpartial rendering based on user 201 input and job information 213 isperformed. In another embodiment, determining page content forreader-spread or arrangement layouts can be derived from imposition 421.This has the advantage of including marks that are defined separatelyfrom the page description 452. In this embodiment, job informationsoftware 120 first generates an imposed layout from imposition 421. Thenit extracts a portion of the imposed layout representing the boundary ofa page and saves it as a de-imposed page description.

When double-sided impositions exist, another embodiment of the inventionmay advantageously enable simultaneous display of page layouts for eachsurface. In this embodiment, partial images for both surfaces aregenerated, each corresponding to the same portion (on opposite sides) ofthe medium that is visible in the display. The image rasters arecomposited by client software 110 prior to presentation. The images arepresented to simulate the effect of viewing the images printed on atransparent medium. Based on user 201 input, client software 110 canalter either image's pixel values to facilitate comparison of content(e.g. to ensure that pages are aligned on the front and back surfaces).For example, the intensity of one image can be reduced highlight thefeatures of the other image, or the colors of one image can be alteredto colors that will contrast with the other image. “Software BasedProofing Method For Double Sided Printing”, the title of U.S. Pat. No.5,625,766, describing additional double-sided soft proofing methods isincorporated by reference herein.

The invention has been described in detail with particular reference tocertain preferred embodiments thereof, but it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention.

PARTS LIST

-   101A-C client locations-   102A-C server location-   110 client software-   110A-C client software-   120 job information software-   120A-C job information software-   130 multiple job databases-   130A-B job databases-   140 print production software-   140A-C print production software-   150 computer system network-   150A-D networks-   201 user-   206 print product-   207A-B job update-   210 start-   211 job information-   212 job information-   213 job information-   214 job display-   215 select job information-   216 job detail display-   220A-B page layout view-   221A-B view information-   222A-B layout image-   223A-B page layout information-   224A-B generate page layout-   225A-B partial page layout-   226A-B partial layout image view-   230 page action-   231 page request-   232 job update request-   301 reader-spread page layout-   310 left-side page-   311 page content-   312 page content-   313 page content-   314 trim box-   320 right-side page-   401 multiple jobs-   402 exemplary job-   410 job identifier-   420 multiple impositions-   421 imposition-   422 multiple signatures-   423 signature-   424 marks-   425 marks-   426 plurality of sheets-   427 sheet-   428 surfaces-   429 one surface-   429A front surface-   429B back surface-   430 plural of geometries-   431 one geometry-   431A-L geometries-   440 multiple page sets-   441 page set-   441A page set-   441B page set-   442 page positions-   443 page positions-   443A-M page positions-   450 multiple pages-   451 page-   452 page description-   452A-D page descriptions-   501 line-   502 line-   503 line-   510 reader-spread position

1. A method for viewing a layout at a client location comprising:obtaining information about a front-side and back-side arrangement ofpage descriptions at a client location wherein the arrangementscorrespond to information to be printed on a front-side and back-side,respectively, of a single medium; communicating a layout view request toa server location based on the information about the front-side andback-side arrangement of page descriptions; generating at least onepartial layout image at the server location based on the layout viewrequest; communicating the at least one partial layout image to theclient location; and displaying the at least one partial layout image atthe client location.
 2. A method according to claim 1 whereincommunicating the layout view request comprises communicating:information about the front-side and back-side arrangement of pagedescriptions for a pair of layouts; and information about a part of thepair of layouts to be viewed.
 3. A method according to claim 2 whereincommunicating the information about the part of the pair of layouts tobe viewed comprises communicating: information about a part of one ofthe layouts to be viewed; and information about whether to view theother layout.
 4. A method according to claim 2 wherein generating the atleast one partial layout image comprises: determining a front-side andback-side layout description based on the information about thefront-side and back-side arrangement of page descriptions; and renderinga part of at least one of the layout descriptions to form the at leastone partial layout image wherein rendering is based on the informationabout the part of the pair of layouts to be viewed.
 5. A methodaccording to claim 4 wherein rendering the part of at least one of thelayout descriptions to form the at least one partial layout imagecomprises: determining a front-side part of the front-side layoutdescription and a back-side part of the back-side layout descriptionbased on the information about the part of the pair of layouts to beviewed wherein the front-side part and the back-side part, when renderedfor display, occupy the same area of the display; and rendering at leastone of the front-side part or the back-side part to form the at leastone partial layout image wherein rendering the back-side layoutdescription comprises transforming the back-side layout image to bemirror-imaged and in correct spatial alignment with the front-sidelayout image such that simultaneous display of the front-side andback-side layout images simulates the appearance of printing on atransparent medium.